行波效应下对称多跨大跨结构的随机地震响应研究  

A study on the random seismic response of large symmetric multi-span structures to wave-passage effect

作　　者：赵博[1] 王元清[2] 陈志华[1] 石永久[2] 

机构地区：[1]天津大学建筑工程学院,天津300072 [2]清华大学土木工程系土木工程安全与耐久性教育部重点实验室,北京100084

出　　处：《振动与冲击》2016年第20期9-16,共8页Journal of Vibration and Shock

基　　金：国家自然科学基金重点项目(51038006);高等学校博士学科点专项基金资助课题(20090002110045)

摘　　要：为了研究行波效应对于多跨大跨结构随机地震响应的影响机理,首先以两跨结构简化模型为研究对象,选取柱顶相对位移作为计算响应量,采用多点虚拟激励法对结构的响应功率谱公式进行推导,求得结构响应极值随行波频率的变化规律,最后将此方法拓展至多跨结构,分析不同跨数以及不同支承形式对于多点激励下结构地震响应的变化规律。计算结果表明:受拟静力响应影响,多跨结构中柱柱顶相对位移受行波效应影响更加显著,在大跨结构抗震设计中应该引起重视;随着跨数增加结构响应极值并没有明显提升,但不同支承形式可能导致结构受多点激励效应影响不同,针对具体的支承形式结构进行具体分析是必要的。This paper aimed at studying the influence mechanism of the seismic response of large multi-span structures to wave-passage effect. A simplified two-span structural model was firstly studied and the relative displacement of columns was used as the response. The response power spectrum density formulae were derived by the multi-support pseudo excitation method. The changing law of the structural seismic peak response with wave-passage frequency was also calculated. These procedures were extended to study the influence of different amounts of spans and different supporting forms to the structural seismic response of multi-span structures. The result shows that： due to the pseudo static response, the relative displacement of the middle columns is larger than the comer columns and it should be paid more attention in structural seismic design; the peak response does not increase significantly with the increase of spans; however, different supporting forms may lead to distinct response. It is thus necessary to calculate the structural response to multi-support excitations according to a specific supporting form.

关 键 词：行波效应 多跨大跨结构 虚拟激励法 柱顶相对位移 不同支承形式 

分 类 号：TU311.3[建筑科学—结构工程] O327[理学—一般力学与力学基础]